Punch head with punch-cut replaceable dies



Sept. 20, 1966 A F1 BROCK PUNCH HEAD WITH PUNCH-CUT REPLACEABLE DIES Filed Sept. 22, 1964 INVENTQR.

ARTHUR F B/QOOK United States Patent O 3,273,438 PUNCH HEAD WITH PUNgH-CUT REPLACEABLE DIE Arthur F. Brook, Poughkeepsie, N.Y. Filed Sept. 22, 1964, Ser. No. 398,363 1 Claim. (Cl. 253-685) The invention herein relates by way of example to the punches employed in the machines for folding and punching book cover blanks disclosed in patent application Serial No. 393,174, filed August 31, 1964, in which there are a plurality 'of punch elements cooperating with a plurality of companion dies, involving special problems in maintaining accurate alignment and registration and the cost of substitution of accurate new for worn or injured parts and the like.

Objects of the present invention are to avoid and so far as possible overcome such disadvantages or objections.

This has been accomplished by constructing the punch head with dies made up of approximate die shape, faced with die forming sheet material adapted to be punched to the exact die shape by the companion punch elements which are to cooperate with such dies.

This results in each die being cut to the exact conformation of the companion punch and means that worn or injured dies can be immediately replaced by the substitution of a new sheet of die face material and operation of the companion punch to accurately finish that die.

Other novel features tof the invention and desirable objects attained are set forth and will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates a present practical embodiment of the invention. Structure, however, may be modified and changed as regards the immediate illustration; all within the true intent and scope of the invention as hereinafter defined and claimed.

FIG. 1 is a side elevation of the punch head with parts broken away and in section to more clearly show the details of construction.

FIG. 2 is a top plan view of the same, with parts broken away and appearing in section.

FIG. 3 is a broken sectional detail on substantially the plane of line 3--3 of FIG. l.

FIG. 4 is a broken perspective view of one of the spring steel die plates after being cut by the companion punch.

The punch head shown consists of a body lor bolster part 7, constructed for mounting in the machine with which the punch is used and carrying the row of punches 8 cooperating with a die made up of an approximate die form 9 faced with an exact die form `10, conformed to the companion punch element 8.

The punches have heads 11 at their outer end for engagement with the reciprocating slide or other actuating member and they are shown as guided in grooves y12 cut in the base and closed over the top by a cover plate 13.

The dies are similarly constructed, with a die plate 14 grooved in the top at 15, to form the die cavities and closed over the top by cover plate 16.

The die plate is shown backed up by a supporting plate 17, both secured to the bed by bolts 18.

The die cavities 15 are made slightly oversize to freely accommodate the punches and the exactness of fit desired for the punches is effected by provision of an overlying strip 19 of a die forming material such as spring steel,

fixedly but removably secured over the face of the die plate.

In the illustration, this die face plate 19, FIG. 4 of spring steel or other material suited to the formation of a die for cutting the material for which the punch head is designed, is preformed with an `angularly bent upper edge portion 20 for stiifening and bracing this sheet material and to provide a grip for firmly securing the plate in place.

As shown particularly in FIG. l, the main portion of the sheet material is gripped between the face of the die plate `14 and a clamp bar 21 seated in the cavity 22 in the base piece.

The overturned angular flange portion 20 of the die face sheet is shown as gripped between the cover plate 16 and an overstanding plate 23, carrying the flange gripping screws 24.

The clamp plate 23 is shown in FIG,I 1 as releasably secured on the back-up plate 17 by screws 25,

Discharge ports 26 for scrap are shown provided in the back-up plate in line with the die cavities.

The thin spring steel sheet may be of conventional tempered spring steel or tempered stainless spring steel. With this material, the chip breaks away cleanly.

In practice, the strip may be heat treated ahead of time after bending to a right angle.

The die under the facing strip is hard so as not to distort after long usage.

The punches may be heat treated to assure punching by them of the cover strip.

The punching of the final, exact die shapes by the male punches assures subsequent accurate punch operation and as Wear or possible breakage occurs, a whole new set of accurate dies can be provided by simply loosening the holding screws, taking out the die facing strip and replacing it with a fresh uncut strip and then after securing in place, cutting the die openings by the punches which are to cooperate with such dies.

What is claimed is:

Punch head with punch-cut dies comprising,

a row of punches for punching a row of perforations in paper or other material,

companion dies yfor the respective punches,

said dies consisting each of a permanent die bed having a die cavity closely approximating the size and shape of the companion punch and freely receiving said punch and a sheet of angularly bent thin die forming material suited to the punching of the material for which the punch head is designed, said sheet of die forming material overlying said die bed and being penetrable by said punch, and

releasable means in -the form of a clamp gripping the angularly bent portions of said sheets: and rixedly oonfining said sheet of die forming material over said die cavity in the die bed,

said sheet having a final exact die :forming perforation therein produced by the companion punch and forming an exact die fitted to said punch in line with the die cavity in the die bed and thereby adapted for the punching of accurately sized perforations in paper or other material and whereby upon release of said confining means the punch-cut sheet of final die forming material may be removed and be replaced by a fresh sheet and be 3 4 cut to accurate die forming shape by the companion 2,562,678 7/ 1951 Okumura 83-618 punch members. 2,568,152 9/ 1951 Hermann 83-690 2,568,863 9/1951 May 83-618 X References Cited by the Examiner 2,745,492 5/ 1956 Brook 83-618 X UNITED STATES PATENTS WILLIAM .DY R, 345,189 7/1886 stimpson et a1 a3-687x W E JR P nmaryExaml'le 1,070,887 s/1913 Hartog 83-690 X FT-YOSTJSSISMMEMMIHW- 

